Added Material UI 4 import rule to plugins/apache-airflow

Signed-off-by: Aditya Kumar <aditya.kumar60@infosys.com>

.changeset/big-dancers-deliver.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-apache-airflow': patch
+---
+
+added an optional ESLint rule - no-top-level-material-ui-4-imports - which has an auto fix function to migrate the imports and used it to migrate the imports for plugins/apache-airflow

plugins/apache-airflow/.eslintrc.js

@@ -1 +1,5 @@
-module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname, {
+    rules: {
+      '@backstage/no-top-level-material-ui-4-imports': 'error',
+    },
+  });

plugins/apache-airflow/src/components/HomePage/HomePage.tsx

@@ -22,7 +22,7 @@ import {
   Page,
   SupportButton,
 } from '@backstage/core-components';
-import { Grid } from '@material-ui/core';
+import Grid from '@material-ui/core/Grid';
 import React from 'react';
 import { DagTableComponent } from '../DagTableComponent';
 import { StatusComponent } from '../StatusComponent';

plugins/apache-airflow/src/components/LatestDagRunsStatus/LatestDagRunsStatus.tsx

@@ -18,17 +18,15 @@ import { apacheAirflowApiRef } from '../../api';
 import useAsync from 'react-use/lib/useAsync';
 import { DagRun } from '../../api/types/Dags';
 import { useApi } from '@backstage/core-plugin-api';
-import {
-  Box,
-  Button,
-  CircularProgress,
-  List,
-  ListItem,
-  ListItemIcon,
-  makeStyles,
-  Tooltip,
-  Typography,
-} from '@material-ui/core';
+import Box from '@material-ui/core/Box';
+import Button from '@material-ui/core/Button';
+import CircularProgress from '@material-ui/core/CircularProgress';
+import List from '@material-ui/core/List';
+import ListItem from '@material-ui/core/ListItem';
+import ListItemIcon from '@material-ui/core/ListItemIcon';
+import Tooltip from '@material-ui/core/Tooltip';
+import Typography from '@material-ui/core/Typography';
+import { makeStyles } from '@material-ui/core/styles';
 import {
   Link,
   StatusError,